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Bottlebrush polymers are a unique class of materials where each individual repeating unit in the polymer chains are polymers themselves. In other words, they can be defined as ‘polymers of macromonomers’. Recently, bottlebrush polymers have attracted significant attention of researchers due to their unique structural landscape and mechanical properties similar to gels and other soft materials. However, straightforward synthetic procedures to obtain bottlebrush materials with relatively long side-chains are still ill-defined in the literature. Thus, polymerizations of large macromonomers remain challenging task. To achieve this goal, we selected the facile ring-opening metathesis polymerization (ROMP) based ‘graft-through’ strategy which provides 100 % grafting density and well-defined materials with narrow dispersion, that means well controlled, in very short reaction times (within hours). We designed a small molecule which enables two orthogonal polymerization techniques independent of each other. Using this small molecule, following the synthesis of a desired polymer via atom transfer radical polymerization (ATRP), a ROMP in the orthogonal direction easily provides a bottlebrush material in only two steps. Currently, we are able to obtain large macromonomers (10 kg/mol) with narrow dispersions (<1.1) by tuning reaction condition. These macromonomers were characterized using size exclusion chromatography (SEC) and can be polymerized via ROMP. Future work involves synthesizing new bottlebrush polymers with these macromonomers and breaking the limit of bottlebrush polymers.